Add test and fix for 9203, fix sdk dep, delete unused file.

pkg/serialization/lib/src/serialization_rule.dart

Index: pkg/serialization/lib/src/serialization_rule.dart
diff --git a/pkg/serialization/lib/src/serialization_rule.dart b/pkg/serialization/lib/src/serialization_rule.dart
index 408d40b3f228e8df53943d6e6e6da67f4fa55bfd..01b3b0535f528aeda96b953ff686135148c65cce 100644
--- a/pkg/serialization/lib/src/serialization_rule.dart
+++ b/pkg/serialization/lib/src/serialization_rule.dart
@@ -398,8 +398,9 @@ class MirrorRule extends NamedObjectRule {
     var qualifiedName = r.resolveReference(state.first);
     var lookupFull = r.objectNamed(qualifiedName, (x) => null);
     if (lookupFull != null) return lookupFull;
-    var lib = qualifiedName.substring(0, qualifiedName.indexOf("."));
-    var type = qualifiedName.substring(qualifiedName.indexOf(".") + 1);
+    var separatorIndex = qualifiedName.lastIndexOf(".");
+    var lib = qualifiedName.substring(0, separatorIndex);
+    var type = qualifiedName.substring(separatorIndex + 1);
     var lookup = r.objectNamed(type, (x) => null);
     if (lookup != null) return lookup;
     var libMirror = currentMirrorSystem().libraries[lib];
@@ -541,6 +542,7 @@ class _LazyList extends Iterable implements List {
   Iterator get iterator => _inflated.iterator;
   indexOf(x, [pos = 0]) => _inflated.toList().indexOf(x);
   lastIndexOf(x, [pos]) => _inflated.toList().lastIndexOf(x);
+  sublist(start, [end]) => _inflated.sublist(start, end);
 
   Map<int, dynamic> asMap() => IterableMixinWorkaround.asMapList(this);